Magnetic induction device



June M, W49. c. G. SMITH MAGNETIC INDUCTION DEVICE 5 Sheets-Sheet 1 Filed July 24, 1946 /NVENTOR CHARLES G. SMITH @Y M BTL EV Mime l@ E949. Q G, SMH-H MAGNETIC INDUCTION DEVICE 3 Sheets-Sheet 2 Filed July 24, 1946 RH Y 7 E @MQW NS MGI@ NG m /w .MY @N NN Guilin-i Il ml l I l I.

dumme 14, i949. Q G, SMITH 2,473,477

MAGNETIC INDUCTION DEVICE 5 Sheebs-Sheet 3 Filed July 24, 1946 8 ELECT/POMAGNETS 3Q F16, 3

fm L/ ,DL/ASE T /N VERTE/2 /eECT/F/ER ALTERAmT/NG VOLTAGE Sli/#T552 GENERATOR sw/m//NG 44 l l MEc/AN/SM F/sEouE/vcv F/aEouEA/cv D/V/DE/s MULT/PL/Erz` VARY/N6 PULSE PHASE AMPL/TUDE pOLA/2m, /M/E/QTE/z` PULSE. SW/TCH GENE/Arora Lm, tal 22 /7 v v\33 PA TH- coNTQoLL/N@ ELECT/@MAGNETS V /NvENToR CL/ARLEsCSm/TH @MEME Patented June 14, 1949 MAGNETIC INDUCTION DEVICE Charles G. Smith, Medford; Mass., assignor to Raytheon Manufacturing Company, Newton, Mass., a corporation of Delaware Application July 24, 1946, Serial No. 685,939

8 Claims. l

This invention relates to magnetic induction devices for accelerating charged particles, such as electrons, so as to cause the same to attain masses and velocities representing energies in the hundreds of millions of electron-volts, and constitutes a continuation-impart of the invention disclosed in the copendng application entitled "Magnetic induction devices, Serial No. 681,904, led July 9, 1946.

Existing devices intended to attain the abovestated objective have suffered from the disadvantage of being limited, in imparting acceleration to the charged particles, to not more than a halicycle of the driving electromotive force. In addition, such devices have required inordinately large amounts of iron to impart to the charged particles a given amount of energy.

It is, therefore, an object of the present invention to provide a magnetic induction device of the general character indicated which enables the repeated acceleration of the charged particles during many half-cycles of the driving electromotive force, thereby more easily attaining, with relatively weaker driving force, the extremely high energy desired.

It is another object of the present invention so to construct the above referred to magnetic induction device as to require, in order to arrive at a deiinite energy, the incorporation therein of considerably less iron than has heretofore been the case, thereby materially reducing cost, weight and size.

It is a further object of the present invention generally to improve the art of magnetic induction devices.

These and other objects of the present invention, which will become more apparent as the detailed description thereof progresses, are attained, brieiiy, in the following manner:

An evacuated envelope, made, preferably, of glass, and consisting, preferably, of a centrallydisposed, main body portion from which extends, in opposite directions, a pair of loop-like, auxiliary body portions communicating with said main body portion, is provided with means, for example, a conventional electron gun, for introducing electrons therein.

Spaced about at least a portion of one of the auxiliary body portions of said envelope is a plurality of means, preferably, electromagnetic, for establishing a plurality of magnetic elds transversely therethrough, said fields being constant or time varying, and acting upon the electrons emitted by said gun to subject the same to a rst force the direction of which is perpendicular to the direction of said elds, whereby said electrons are caused to move in a first closed path including the main body portion and the last-mentioned auxiliary body portion of said envelope.

Also spaced about at least a portion of the I last-mentioned body portion of said envelope is a plurality of means, preferably, electromagnetic, for establishing a plurality of time-varying magnetic fields linking said rst closed path, said time-varying magnetic fields inducing a plurality of electromotive forces along the length of said iirst closed path, whereby the electrons moving therein are subjected to a second force which causes the same to become accelerated.

The main body portion of said envelope is provided with means, preferably, partially electromagnetic and partially electrostatic, for switching, after the iirst half-cycle of the driving electromotive force, the electrons accelerated as above, from said first closed path to a second closed path which includes the main body portion and the remaining auxiliary body portion of said: envelope.

The last-mentioned auxiliary body portion of said envelope, like said rst-mentioned auxiliary body portion, is provided with a plurality of means, preferably, electromagnetic, for subjecting the accelerated electrons received therein to a third force which causes the same to move in an orbit encompassing said second closed path. The last-mentioned auxiliary body portion of said envelope is also provided with a plurality of means, preferably, electromagnetic, for subjecting said accelerated electrons to a fourth force In the accompanying specification there shall be described, and in the annexed drawings shown, an illustrative embodiment of the magnetic induction device of the present invention. It is, however, to be clearly understood that the present invention is not to be limited to the details herein shown and described for purposes of illustration only, inasmuch as changes therein may be made without the exercise of invention, and within the true spirit and scope of the claims hereto appended.

In said drawings,

Fig. 1 is a longitudinal sectional view. taken substantially through the center of a magnetic induction device assembled in accordance with the present invention;

Fig. 2 is a transverse sectional line 2-2 of Fig. l; and

Fig. 3 is a schematic diagramfof one way inv which the electrical components included in the present invention may be connected to a power source.

Referring now more in detail to the aforesaid illustrative embodiment of the present invention, with particular reference to Figs. 1 and 2 of the view taken lon drawings, the numeral I generally designates cates, atthe opposite lends thereof, with-said' main. body portion I I.

Mounted at one end of theimain body portion f II is an.` electrony gun Mcomprising an electronernissive cathode I5, a perforate accelerating electrode .l ligand a perforate focusing electrode I'I, wherebya thin` stream of electrons can be introducedinto thefinterior'of saidenvelope I 0. Mounted'within the main-body portion II is a pairof I.conducting plates'l and I9 between which, as will hereinafter be ymore fully described, ari-.electric feldis adapted tobe established, and surrounding said-main bodyportion II is a coilk 20..by means of which, alsozas will hereinafter be more ijullydescribed, amagnetic yeld-is adaptedto be established lengthwise throughsaidsrnainV body portion, parallel .to and. intermediate the Plates- !8 .and l9 The mutually perpendicular electric and mag;v

netic-elds thus established are-in such directions, andare vof suchrelative intensities, that the stream of electrons .coming from. the gun I4. i

isl deflected, as yindicated by the broken line marked A,. so as to enter the lower curved portion 2l of the auxiliary body-portion I2.

Disposedat spaced intervals .about the lower, portionzl `of the auxiliary body .portion AI 2 isa plurality of substantially U-shaped electromagnets. ,22,V alternate magnets having their pole pieces .23 and 24 straddlingthe envelope andcon; verginginwardly, and intermediate magnets hav.- ing their pole pieces-25 and26 straddling the envclope and diverging outwardly, whereby.' there is established along the lengthfof the lower portionZI of the auxiliary body portion -I 2 a plurality of transverse magnetic lields the lines of yforcev of which bow outwardly. The radial variation in these-fields should be such as to result in stabilizingthe orbits of the moving electrons.

"Ihe interaction of the magnetic fieldsv thus established.y with the Ymoving. electrons fenteringj the lower portion 2l of the auxiliary body, portion.. I 2 ,cruisessaid electrons to ,be subjected toa-force which-holdsthem in a path `following the corr-V tour of said lower portion 2|. The electrons,- in the device as thus far fdescrixbedgmoveat a snbf spatially uniformV speed ,Substantially equal'te 4 that with which they are emitted from the gun I4.

As the electrons leave the lower curved portion 2| of the auxiliary body portion I2, they enter a straight portion 21, and in order to accelerate said electrons, it is necessary to subject them to one or more electromotive forces along the length of their orbit. For this purpose, a plurality of circular velectromagnets 28 is disposed along the length of the straight portion 2'I of the auxiliary body portion I2, said electromagnets linking the electron orbit within the envelope and, preferably, beingcoaxial therewith.

Eachsuch electromagnet may comprise a closeljcore .29, which may be laminated, provided lwith a .winding 30 uniformly distributed there- `about in such a manner that after coming around ,to the starting point, it winds back upon itself until it again returns to said starting point, all of the turns of said winding being in the same direction. When such a winding is energized, a magneticeldis established within the core, but -no field lappears externally of said core. and when the energizing current is varied with time, said iield` givesv rise to a time-varying electromotive part of said magnetic field, however, invading the region con-taining said electromotive force. As the movingfelectrons are impelled by the drivingelectromotive force thus created along the length of the-straight portion Z'I of the auXiilary body portiony I2, lthey are accelerated.

Asthe accelerated electrons leave the straight portion'Zl of the auxiliary body portion I2, they enter 'an-,upper curved portion 3l which, like the lower curved portion 2|, is provided along the lengththereof with a plurality of path-controlling elect'romagnets 22.

Asthe electrons leave the upper curved portion 3| of the A(auxiliary body portion I2, they returnv to ,the main'body portion II, and move in a straight line therethrough to complete a rst closed path, whereupon they again enter the lower cu'ryed portion 2I to start another excursion around saidfirst closedv path. Said rst closed path has been indicated in the drawings by the broken line marked B.

The Velectromagnets 28 may be energized, as will hereinafter be more fully described, by a cycle alternating current, and during the first positive` alternation of said current, the electrons make inany. excursions about the path B, each excursion resulting in acceleration to a greater velocity- Means, to be hereinafter more fully described, are provided whereby at the end of the above referred to first positive alternation of the current energizing the electromagnets 28, an electric field is established between the plates I8 and I9 in such direction that, in cooperation with the magnetic iield of the coil 2t, it causes the electrons entering the main body portion I I from the upper curved portion 3| of the auxiliary body portion I 2 to be deflected so as to move along the Path indicated in the drawings by the reference character C and enter the lower curved portion S 4.of the auxiliary body portion I3 of the envelope I spaced alongthe length of the lower curved portion 3263i the auxiliary body portion I3 is a plurality of elyectromagnets 33, similar to the electrornagnet's 22, but so energized that the elds thereof are oi opposite polarity for the reason tliahwh'e're as in` the vauxiliary body portion I2,

theelectron ,movement was assumed to be in a 7.5 clockwise'direction, in the auxiliary lbody por-Y force along the axis of said electromagnet, no-

tion I3, it will be seen that the electron movement is in a counter-clockwise direction. Also, as in the case of the electromagnets 22, the pole pieces 3i and 35 of alternate electromagnets 33 straddle the envelope and converge inwardly, while the polel pieces 36 and 31 of intervening electromagnets 33 straddle the envelope and diverge outwardly.

As the electrons leave the lower curved portion 32 of the auxiliary body portion I3, they enter a straight portion 38 which, like the straight portion 2l of the auxiliary body portion I2, is linked by a plurality of circular electromagnets 38. The latter include laminated cores 4Il and windings 4I, said windings 4I being energized in phase opposition to the energizing of the electromagnets 28 linking the straight portion 2l. By this, it is meant that in the device as shown in Fig. l, the electromotive forces induced by the electromagnets 28 and 3S are displaced in timeI phase by 136. Thus, the electrons entering the straight portion 3B of the auxiliary body portion I3 are additionally accelerated.

As the additionally accelerated electrons leave said straight portion 38, they enter the upper curved portion 42 of the auxiliary body portion I3, wherein, by means of another group of electromagnets 33, they are guided back to the main body portion il, through which, in the absence of any electric eld between the plates Ill and I9, they pass to again enter the lower curved portion 32 of the auxiliary body portion I3, thereby completing an excursion through a second closed path, indicated by the reference character D.

During the first positive half-cycle of the current energizing the electromagnets 39, the electrons make many excursions over the path D, and with each excursion they become still further accelerated. As the end of said halfcycle, an electric field, of opposite polarity to the eld which caused the electrons to move from path B to path D by way of path C, is established between the plates I8 and It, whereby said electrons are caused to reenter the lower curved portion I2, by way of the path marked E, and commence additional excursions over the path B.

By thus switching the electrons between the paths B and D at the end of each ha i`cycle of the driving electromotive lforce, tremendous velocities and alterations in mass are obtained after a few cycles of said driving force. After a predetermined number of such cycles, the in tensity of the electric eld established between a the plates i8 and I9 may be made such as to result in the electrons passing out of the main body portion I! through the end d3 thereof, whereupon the energy gained by said electrons may be put to any appropriate use.

In order to prevent negative space charge from reducing the number of electrons travelling in the closed orbits hereinbefore referred to, it is desirable to provide the inner surfaces of the auxiliary body portions I2 and i3 of the envelope It! with a plurality of spaced metallic coatings IIl, each of said coatings being connected to the positive terminal of a source of voltage (not shown), the negative terminal of which may be connected to the cathode I 5 of the electron gun i4. Preferably, the potential of said coatings with respect to the cathode of said gun should be about the same as the potential of the accelerating electrode I of said gun.

Reference is now made to Fig. 3 of the drawings, wherein a schematic diagram for electrically connecting the components of the device of the present invention is set forth.

As there shown, a portion of the output of an alternating voltage generator lid, which may be of a frequency, for example, oi 60 cycles per second, is applied to the accelerating electromagnets 28 to induce an electromotive force the auxiliary body portion i2 oi the envelope I0, the. direction of said electromotive force being assumed to be such as to drive the electrons about the closed path B in 3, clockwisedirection viewing Fig. l.

Another portion of the output of the generator it is applied through a phase inverter d5, to the accelerating electromagnets to induce an clectromotive force in the auxiliary body portion I 3 of the envelope Iii, the direction of said last-named electrornotiw force being such as to drive the accelerated electrons switched from the auxiliary body portion i2 to the auxiliary body portion I3 about the closed path D in a counter-clockwise direction viewing Fig. i, the phase inverter d5 displacing the electromotive forces developed by the electromagnets Zd and 353 in time phase by A third portion of the output of the generator i4 is applied to a rectifier (iii, the resulting direct current being applied to the coil .Mi in such directiony for example, that the north magnetic pole of the coil 2d is located adjacent the end of the main body portion ii opposite the electron gun I 4.

A fourth :portion of the output of the generator t is applied, through a phase shifter All, to a frequency multiplier d8, for example, a fre quency doubler, and the output of the latter is applied to a pulse generator iii adapted to transform the sine-wave output of the generator i4 into flat-topped pulses of extremely short duration. for example, .l microsecond, said generator le also including means for increasing the amplitude of successive pulses gener. ted thereby over a predetermined number of cycles i the initial voltage produced by the generator The pulses thus obtained are appiied to the plates I8 and IS through a switch designed to reverse the polarity of successive pulses.

The purpose of the frequency multiplier i8 is to enable the production of a pulse corresponding to each half-cycle of the driving electroniotive force; the purpose of the phase shifter lll is to enable the adjustment of the time of the application of the switching pulses to coincide with the end of each half-cycle of said driving electromotive force; the purpose of increasing the amplitude of successive pulses produced by the generator 49 is to take into account the increased velocity of the electrons at each successive switching operation; and the purpose of the polarity switch 50 is to enable reversal of the direction of the electric iield set up between the plates I8 and I9 during successive switching operations so that, at one time, the electrons are deflected away from the path B to the path D, and, at the next time, from the path D back to the path B.

A fth portion of the output of the generator M is applied to a frequency divider 5I, one portion of the output of the latter being applied to the path-controlling electromagnets 22, and another portion of said output being applied, through a phase inverter 52, to the path-controlling electromagnets 33.

Assuming that the Velectrons'are Vto be accelana-,117

erated during vesuccessive cycles of. the voltage produced-by. the generator .Mit/is necessary that each time, during, lsaid vef'cycles, that the electrons pass by the path-controlling electromagnets, the elds establishedv by the latter be of increased intensity in order to compensate for the augmented velocity attained by said electrons with each excursion. This-may be accomplished by applying to the path-controlling electromagnets energizingcurrent of a sub-multiple frequency of the driving electromotive force. In the case under consideration, inasmuch as the gradually increasing' field intensitymust cover the time of five cycles of the driving electromotive force, the frequency ofthe energizing current applied to the path-controlling electromagnets should be three cycles per. second.

This completes the description of the aforesaid llustrative embodiment ofthe present invention. It will be noted from all of the foregoing that by means of the magnetic induction device of the present invention, charged particles, such as electrons, may be repeatedly accelerated during many half ,cyclesof the driving electromotive force, thereby enabling the attainment, with less driving forcethan has heretofore been used, of extremely high energies. It will further be noted that the magnetic induction device of the present invention is so constructed that it is necessary to incorporate therein, in order to arrive at a given energy, considerably less iron thanhas heretofore been the case, thereby materially reducing the cost, Weight and size of the device.

Other objectsand advantages of the present invention will readily occur -to those skilled in the art to which the same relates.

What is claimed is:

1. A magnetic-induction device comprising: an evacuated envelope; a source of electrons, disposed in said envelope, for'introducing electrons therein; a first magnetic structure, mounted adjacent said envelope, for establishing a first magnetic eld transversely therethrough; said rst magnetic field coacting with said electrons to subject them to a rstl force, causing the same to move in a first closed path; a second magnetic structure, linking said envelope, for inducing along said rst closed path a rst, time-varying electromotive force; said .nrst, time-varying electromotive force coacting with the-electrons moving in said rst closed'path to subject them to a second force, causingfthe same to become accelerated-means, mounted adjacent saidfirst closed path, for establishing a third, force-producing eld therethrough;v s'aid third, force-producing eld coacting With'said accelerated electrons to displace the same vfrom said vfirst closed path; 'a third magnetic structure, mounted adjacent said envelope, for establishing a second magnetic eld transversely therethrough; said second magnetic field coacting with-said displaced electrons to subject them to a fourth forceVcausing the same to move in a second closed path; and a fourth magnetic structure,H linking -'said' envelope, for inducing alongsaidsecond'closed path a second, time-varying electromotive. force;` said second, time-varying ,electroniotive force coacting with the electrons moving in said second lclosed path to subject themlto ya fifth force, causing theysame to become additionally accelerated.

2. A magnetic-induction device comprising: an evacuated envelope; asource of electrons, disposed in said envelope, for introducing electrons therein; a iirst magnetic structure, vmounted adjacent said envelope, for establishing a first mag netic field transversely therethrough; said rst.

magnetic iield coacting with said electrons to subject vthem to a rst force, causing the same to move in a first closed path; a second magnetic structure, linking said envelope, for inducing along said rst closed path a rst, time-varying electromotive force; said rst, time-varying electromotive force coacting with the electrons moving in said first closed path to subject them to a second force, causing the same to become accelerated; a third magnetic structure, mounted adjacent said envelope for establishing a second magnetic eld transversely therethrough; said second magnetic eld coacting with said accelerated electrons to subject them to a third force, causing the same to move in a second closed path; a fourth magnetic structure, linking said envelope, for inducing along said second closed path a second, time-varying electromotive force; said second, time-varying electromotive force coacting with the electrons moving in said second closed path to subject them to a fourth force, causing the same to become additionally accelerated; and a partially magnetic, partially electrostatic structure, mounted adjacent said closed paths, for recurrently establishing magnetic and electrostatic elds therethrough; said last-named magnetic and electrostatic elds coacting With said electrons to subject them to a fifth force, causing the same to switch successively between said closed paths.

3. A magnetic-induction device comprising: an evacuated envelope having a main body portion, and two auxiliary body portions extending from and communicating with said main body portion; a source of electrons, disposed in the main body portion of said envelope, for introducing electrons therein; a rst magnetic structure, mounted adjacent one of the auxiliary body portions of said envelope, for establishing a first magnetic field transversely therethrough; said rst magnetic field coacting with said electrons to subject them to a iirst force, causing the same to move in a first closed path including the main and said one of said auxiliary body portions of said envelope; a second magnetic structure, linking said one of said auxiliary body portions of said envelope, for inducing along said first closed path a first, time-varying electromotive force; said first, time-varying electromotive force coacting with the electrons moving in said rst closed path to subject them to a second force, causing the same to become accelerated; means, mounted adjacent said iirst closed path, for establishing a third, force-producing field therethrough; said third, force-producing eld coacting with said accelerated electrons to displace the same from said first closed path; a third magnetic structure, mounted adjacent the other of the auxiliary body portions of said envelope, for establishing a second magnetic eld transversely therethrough; said second magnetic eld coacting With said displaced electrons to subject them to a fourth force, causing the saine to move in a second closed path including said main and said other of said auxiliary body portions of said envelope; and a fourth magneticlstructure, linking'said other of said auxiliary body portions of said envelope, for inducing along said second closed path a second, time-varying electromotive force; said second, time-varying electromotive force coact-l ing with the electrons moving in said second closed path to subject them to a fth force, causing the same to become additionally,accelerated.

4; A magnetic-induction device comprising: an evacuated envelope having a main body portion, and two auxiliary body portions extending from and communicating with said main body portion; a source of electrons, disposed in the main body portion of said envelope, for introducing electrons therein; a first magnetic structure, mounted adjacent one of the auxiliary body portions of said envelope, for establishing a first magnetic field transversely therethrough; said iirst magnetic field coacting with said electrons to subject them to a first force, causing the same to move in a first closed path including the main and said one of said auxiliary body portions of said envelope; a second magnetic structure, linking one of said auxiliary body portions of said envelope, for inducing along said first closed path a first, time-varying electromotive force; said first, time-varying electromotive force coacting with the electrons mcving in said rst closed path tc subject them to a second force, causing the same to become accelerated; a third magnetic structure, mounted adjacent the other of the auxiliary body portions of said envelope, for establishing a second magnetic field transversely therethrough; said second magnetic vfield coacting with said accelerated electrons to subject them to a third force, causing the same to move in a second closed path including said main and said other of said auxiliary body portions of said envelope; and a fourth magnetic structure, linking other auxiliary body portions of said envelope, for inducing along said second closed path a second, time-varying electromotive force; said second, time-varying electromotive force enacting with the electrons moving in said second closed path to subject them to a fourth force, causing the same to become additionally accelerated; and a partially magnetic, partially electrostatic structure, mounted adjacent said closed paths, for recurrently establishing magnetic and electrostatic fields therethrough; said last-named magnetic and electrostatic iields coacting with said electrons to subject them to a fifth force, causing the same to switch successively between said closed paths.

5. A magnetic-induction device comprising: an evacuated envelope; a source of electrons, disposed in said envelope, for introducing electrons therein; a first group of opposed, alternately converging and dii/erging, U-shaped magnets, each of which partially surrounds said envelope, for establishing a first magnetic field transversely therethrough; said first magnetic eld coacting with said electrons to subject them to a first force, causing the same to move in a first closed path; a nrst group of toroidal electromagnets, each of which links said envelope, for inducing along said first closed path a first, time-varying electromotive force; said iirst, time-varying electromotive force coacting with the electrons moving in said first closed path to subject them to a second force, causing the same to become accelerated; means, mounted adjacent said first closed path, for establishing a third, force-producing :lield therethrough; said third, force-producing field coacting with said accelerated electrons to displace the same from said first closed path; a second group of opposed, alternately converging and diverging, U-shaped magnets, each of which partially surrounds said envelope, for establishing a second magnetic field transversely therethrough; said second magnetic field coacting with said displaced electrons to subject them to a fourth force, causing the same to move in a second closed path; and a second group of toroidal electromagnets, each of which links said envelope, for inducing along said second closed path a second, time-varying electromotive force; said second, time-varying electromotive force coacting with the electrons moving in 4said second closed path to subject them to a fifth force, causing the same to become additionally accelerated.

6. A magnetic-induction device comprising: an evacuated envelope; a source of electrons, disposed in said envelope, for introducing electrons therein; a first group of opposed, alternately converging and diverging, U-shaped magnets, each of which partially surrounds said envelope, for establishing a first magnetic field transversely therethrough; said first magnetic field coacting with said electrons to subject them to a rst force, causing the same to move in a iirst closed path; a first group of toroidal electromagnets, each of which links said envelope, for inducing along said iirst closed path a iirst, time-varying electromotive force; said first, time-varying electromotive force coacting with the electrons moving in said first closed path to subject them to a second force, causing the same to become accelerated; a second group of opposed, alternately converging and diverging, U-shaped magnets, each of Which partially surrounds said envelope. for establishing a second magnetic field transversely therethrough; said second magnetic field coacting with said accelerated electrons to subject them to a third force, causing the same to move in a second closed path; a second group of toroidal electromagnets, each of which links said envelope, for inducing along said second closed path a second, time-varying electromotive force; said second, time-varying electromotive force coacting with the electrons moving in said second closed path to subject them to a fourth force, causing the same to become additionally accelerated; an electromagnet surrounding a portion of said envelope including portions of said closed paths; and a pair of spaced plates mounted in the portion of said envelope surrounded by said electromagnet; said electromagnet and said spaced plates being adapted recurrently to be energized to establish magnetic and electrostatic fields coacting with said electrons to subject them to a fifth force, causing the same to switch successively between said closed paths.

'7.y A magnetic-induction device comprising: an evacuated envelope having a main body portion, and two auxiliary body portions extending from and communicating with said main body portion; a source of electrons, disposed in the main body portion of said envelope, for introducing electrons therein; a first group of opposed, alternately converging and diverging, U-shaped magnets, each of which partially surrounds one of the auxiliary body portions of said envelope, for establishing a first magnetic field transversely therethrough; said first magnetic field coacting with said electrons to subject them to a rst force, causing the same to move in a first closed path including the main and said one of said auxiliary body portions of said envelope; a first group of toroidal electromagnets, each of which links said one of said auxiliary body portions of said envelope, for inducing along said first closed path a rst, time-varying electromotive force; said first, time-varying electromotive force coacting with the electrons moving in said first closed path to subject them to a second force, causing the same to become accelerated; means,

' divergng, U-shapedfrna'gnets; each df ing'vvith said` accelerated-lectrons to displace vche sarne from said rstjclosd pathyam-second "igroup of opposed, alternately ydoin(orging' fgnl'id 7 'ond magnetic field 'transverselymtlirthrough; said second magnetic ileld@ fco'a'cting'with `v-said displaced electrons to"'sul'nj'et'tle'n'xj to a fo' rth tromotive forcecoacting iritV the electrons ing in lsaid second closed pathtosubjlect'jt em to 'a fth force, causing Ithe-same to becoi additionally accelerated.

A magnetic-inductiondevice6mp siigzjan evacuated envelope havingafrnan body p tion, and two auxiliary :body portions ``xtendigfrom Iand 'communicating with said 'mafi'n body portion; a source of electrons, :disposed 'in -tl'e main bo'dy vportion of said 'envelopej'for lintroducn'g'iectrons therein; a rst group of opposed, "alternately'c'onverging and diverging, U -shaped magnets; ach f which partially S'LliliidS'OAI-lffrv 'thev ifiry body portions of said evelpa `for establishing a rst magnetic vfield transversely hrth'dugh; said rst magnetic ld'ooactng with said "elc-4 trons to subject th'e'rn to arst 'forc'5 {causing-the same to move in la `-rs'tf'closed path includi'gjtlie main and said one ofsaid ak'iliary jood-y portions of's'aid'envelo'pe; a'rst'g'oup o'fftoroidal 'lectromagnets', each of Which- `vsaid one of fsid auxiliary body 'portions"of, said envelope',- for inducing along said rst'clos'e'd patlia varying electrornotive or'ceysaid rstfl Y fing k'electro1notive 'forc cba ing With fthe rlectrons moving in said firstolosd path tos'ub-.ict

' Magnets, each of v'vhich partially' surroun'jd's'ftne other offth'e auxiliary body portions lo frs'aid Tntransversely therethrough; said secondr magnetic subject them to'a third'force, causing v'the same to move in 'a "sec'ondc'l'osed pathl including Isaid and said other of fsaid auxiliary bodypqrtions 'o f saidenvelo'pe'; a second group of toroid/'al electromagnets' each of which links said r`t'lier oijsaidv auxiliary body portions or said envelope, `for inducing along'said second closed path a secl'0nd, 'time-varyingelectrornotiye force; said s'c- V9nd, time-varying velec t'r'on'ic'ative force 'coacting "'vvitli vtheA electrons moving in vsaidsejc'ond vclosed 'vfpa'th to subject them toa fonrth force, causing theA same tobecome additionally acceleratedgan ,yectromagnet surrounding `said rnain bodyv porftionof said envelope;r and a pair of spaced plates iniountedrin said 'main body '-portion; said1 electroniag'net and' said spacdplates beingg'a'dapted recurrently to be yenergized to establish `nil'ag'ietic and Aelectr@static fields ooacti'r'g With said electrons to subject thernto 'a fth force, causing tliie sa'rne to switch succe'ss'ivelylietwen said closed paths. l l

' CHARLES 'GLSA/11TH.

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